Abstract:
The dataset comprises ApRES (Autonomous phase-sensitive Radio Echo Sounder) time series from four sites (G1-4) through the grounding zone of the eastern Thwaites ice shelf. The instruments were deployed in early 2020 and recovered in early 2021 as part of the International Thwaites Glacier Collaboration (ITGC) MELT project. The aim was to provide time series of basal melt rates and the vertical strain rate at each site.
The ApRES DAT files were converted to netCDF for publication. Each burst in an ApRES file maps straightforwardly to a group in the corresponding netCDF file. This is a lossless, reversible process.
The data were acquired under funding from ITGC: NE/S006656/1.
Keywords:
ApRES, ITGC, Thwaites Glacier, basal melt rate, ice shelf, vertical strain rate
Nicholls, K., & Holland, D. (2022). Phase-sensitive radar (ApRES) time series data from Thwaites eastern ice shelf, 2020 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/b81bff87-3429-4754-b4b5-c6b58198e744
| Access Constraints: | Data under embargo until July 2023. |
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| Use Constraints: | Data supplied under Open Government Licence v3.0 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/. |
| Creation Date: | 2022-04-28 |
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| Dataset Progress: | Complete |
| Dataset Language: | English |
| ISO Topic Categories: |
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| Parameters: |
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| Personnel: | |
| Name | UK Polar Data Centre |
| Role(s) | Metadata Author |
| Organisation | British Antarctic Survey |
| Name | Keith W Nicholls |
| Role(s) | Investigator, Technical Contact |
| Organisation | British Antarctic Survey |
| Name | David M Holland |
| Role(s) | Investigator |
| Organisation | New York University |
| Parent Dataset: | N/A |
| Reference: | Nicholls, K. W., Corr, H. F. J., Stewart, C. L., Lok, L. B., Brennan, P. V., & Vaughan, D. G. (2015). A ground-based radar for measuring vertical strain rates and time-varying basal melt rates in ice sheets and shelves. Journal of Glaciology, 61(230), 1079-1087. doi:10.3189/2015JoG15J073. Brennan, P.V., L-B Lok, K.W. Nicholls, and H.F.J. Corr (2013), Phase-sensitive FMCW radar system for high-precision Antarctic ice shelf profile monitoring, IET Rad., Son. & Nav., doi:10.1049/iet-rsn.2013.0053. |
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| Quality: | The time series are raw, unprocessed data. They have no breaks. | |
| Lineage: | The datasets were collected using standard ApRES methodology with instrument configuration described in data headers. The radar bandwidth was 200 MHz, centred on 300 MHz with a 1-second chirp length at a power of 20 dBm. Bursts of 20 chirps were collected at 2-hourly intervals. The ApRES DAT files were converted to netCDF for publication, using the bas-apres Python package. |
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| Temporal Coverage: | |
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| Start Date | 2020-01-22 |
| End Date | 2020-12-28 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | -75.21998 |
| Northernmost | -75.19011 |
| Longitude | |
| Westernmost | -104.8247 |
| Easternmost | -104.7924 |
| Altitude | |
| Min Altitude | N/A |
| Max Altitude | N/A |
| Depth | |
| Min Depth | N/A |
| Max Depth | N/A |
| Location: | |
| Location | Antarctica |
| Detailed Location | Grounding zone of the eastern ice shelf of Thwaites Glacier |
| Sensor(s): |
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| Data Collection: | Standard ApRES instruments were used, comprising an RMB2c radar board and a VAB Issue c controller board, with the controller running firmware version 103.1, under the Venom 20180522 issue of the Venom operating system. The ApRES DAT files were converted to netCDF for publication, using the bas-apres version 0.1.0 Python package. |
| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 25 GB |
| Distribution Format | netCDF |
| Fees | N/A |
| Data Storage: | The dataset consists of netCDF4 files, which are a lossless, reversible conversion of the field-acquired ApRES DAT files. Each ApRES DAT file was converted to a corresponding netCDF file. Each burst within the ApRES DAT file was mapped to a group in the netCDF file, with the burst header items becoming group-level attributes, and the burst data stored as a 2D data array. The data are organised by site (G1-4), with each site being a top-level directory containing timestamped subdirectories. |